Younès Kaboul will not return for Tottenham Hotspur until early February at best as he endures frustration during the final phase of his recovery from knee surgery.

The central defender, who underwent the operation at the end of August, had hoped to be out for no longer than four months but a January return date has ruled out by André Villas-Boas. Kaboul, who was the club's most consistent centre-half last season, has not yet begun to work outside the gym. Kaboul has played only once this season – in the defeat at Newcastle United on the opening day.

Tottenham's other long-term defensive injury casualty, Benoît Assou-Ekotto, could be available for a return in Saturday's FA Cup tie at home to Coventry City. The left-back, who has not played since 1 September because of a wear-and-tear knee problem, had been expected to make his comeback over the festive period.

Villas-Boas is relaxed about the need to make January signings, partly because of the encouraging picture with regard to the fitness of his squad, although the manager is open to possibilities that present themselves. If he could make one big signing, it would be the Internacional and Brazil striker Leandro Damião, whom he tried to buy last summer.

Centre-forward is the priority area for Villas-Boas to strengthen, as he has only Jermain Defoe and Emmanuel Adebayor as specialists in the position and it could be that January is the better time in which to move for Damião, as the Brazilian league is in its off-season. Villas-Boas has no great confidence, though, that a deal will be closed for Damião, a player that Tottenham have chased for several transfer windows.

The club are hopeful that Adebayor will not join up with Togo for the Africa Cup of Nations, which begins on 19 January in South Africa, which would represent a boost to their options.

Adebayor has said that his problem with playing at the tournament relates to the Togolese FA's struggles to co-ordinate the logistical arrangements in a satisfactory fashion and to create a safe environment for the squad, rather than his unhappiness at the non-payment of bonuses. Adebayor is haunted by the gun attack on the Togo team bus before the 2010 tournament in Angola, when three people were shot dead.